Đáp án:
\(\begin{array}{l}
a)\\
a = 2,4\\
b = 9,8\\
b)\\
V = 2,24
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
Mg + {H_2}S{O_4} \to MgS{O_4} + {H_2}\\
{n_{{H_2}S{O_4}}} = \dfrac{{100 \times b\% }}{{98}} = \dfrac{b}{{98}}\,mol\\
{n_{MgS{O_4}}} = {n_{{H_2}}} = {n_{Mg}} = {n_{{H_2}S{O_4}}} = \dfrac{b}{{98}}\,mol\\
{m_{{\rm{dd}}spu}} = \dfrac{b}{{98}} \times 24 + 100 - \dfrac{b}{{98}} \times 2 = 100 + \dfrac{{11b}}{{49}}(g)\\
{C_\% } = 11,7416\% \Leftrightarrow \dfrac{{\dfrac{b}{{98}} \times 120}}{{100 + \dfrac{{11b}}{{49}}}} = 11,7416\% \\
\Rightarrow b \approx 9,8 \Rightarrow {n_{Mg}} = {n_{{H_2}}} = \dfrac{{9,8}}{{98}} = 0,1\,mol\\
a = {m_{Mg}} = 0,1 \times 24 = 2,4g\\
b)\\
{V_{{H_2}}} = 0,1 \times 22,4 = 2,24l
\end{array}\)
